Previous methods of extracting lithium values from brines which contain lithium are disclosed in the following U.S. Pat. Nos.: 4,116,856; 4,116,858; 4,159,311; 4,221,767; 4,291,001; 4,347,327; 4,348,295; 4,348,296; 4,348,297; 4,376,100; 4,381,349; 4,430,311; 4,461,714; 4,472,362; and 4,477,367. These patents pertain, in various ways, to creating lithium aluminates within the interstices or pores of ion exchange resins, or on other substrates, porous and non-porous. Microcrystalline lithium aluminates formed within ion exchange resins are useful in selectively removing lithium values from Li-containing brines.
Over the years, it has been found that ion exchange resin compositions were often fouled by substances in the brine, such as hydrocarbon contaminants, that rendered the ion exchange resin incapable of rejuvenation requiring re-manufacture of resin.
In Lithium--Current Applications in Science Medicine and Technology, R. O. Bach Editor, published by John Wiley and Sons, 1985, there is an article on pp. 29-34, authored by W. C. Bauman, J. L. Burba, III and J. M. Lee, titled "Structure And Operation Of Dow's New Lithium-Selective Ion-Exchange Resin" containing some background information of relevance to the subject matter of this present disclosure.
We have now, unexpectedly, found it preferable to infuse LiOH into the polycrystalline hydrated alumina pellets, herein referred to as Al(OH).sub.3, by reacting it, in the presence of water, with LiOH in the absence of NaCl or other salt. We find that infusion of LiOH into Al(OH).sub.3 pellets proceeds with maintenance of pellet integrity up to and beyond 0.2 mol fraction, and up to 0.33 mol fraction of LiOH in the so-formed LiOH/Al(OH).sub.3. Furthermore, we find that having initially prepared the intercalation in the absence of NaCl or other salt, the pellets can then be converted to the LiCl form with aqueous HCl and used for the specific recovery of LiCl from brine without pellet breakage. Our prior work with intercalating LiCl directly into the crystals to form LiCl/Al(OH).sub.3 was limited to amounts of up to about 0.2 mol fraction of LiCl in order to avoid breaking up the pellets. Also, we have now determined that these so-altered polycrystalline alumina pellets containing more than 0.2 mol fraction, up to 0.33 mol fraction, of LiCl in the LiCl/Al(OH).sub.3 produced in the presently described method, offer significant improvements in costs and efficiency for recovering LiCl from brine compared to the material identified hereinabove as being of relevance in "Structure And Operation of Dow's New Lithium-Selective Ion-Exchange Resin."